st72324bk STMicroelectronics, st72324bk Datasheet - Page 22

• Manufacturer Part Number: st72324bk
• Description: 3 V/5 V Range 8-bit Mcu With 4/8 Kbyte Rom, 10-bit Adc, Four Timers And Spi
• Manufacturer: STMicroelectronics

Central processing unit
4.3.4
Reset:
22/167
7
1
Figure 8.
Condition code register (CC)
The 8-bit Condition Code register contains the interrupt masks and four flags representative
of the result of the instruction just executed. This register can also be handled by the PUSH
and POP instructions.
These bits can be individually tested and/or controlled by specific instructions.
Arithmetic management bits
Bit 4 = H Half carry.
RESET VALUE = STACK HIGHER ADDRESS
RESET VALUE = RESET VECTOR @ FFFEh-FFFFh
15
15
This bit is set by hardware when a carry occurs between bits 3 and 4 of the ALU during
an ADD or ADC instructions. It is reset by hardware during the same instructions.
0: No half carry has occurred.
1: A half carry has occurred.
This bit is tested using the JRH or JRNH instruction. The H bit is useful in BCD
arithmetic subroutines.
1
111x1xxx
RESET VALUE = 1
PCH
CPU registers
I1
8 7
8
RESET VALUE = XXh
RESET VALUE = XXh
RESET VALUE = XXh
7
7
7
7
1
7
1 1 X 1 X X
1 I1 H I0 N Z
PCL
H
Read/write
0
0
0
0
X
0
C
0
ACCUMULATOR
X INDEX REGISTER
Y INDEX REGISTER
PROGRAM COUNTER
CONDITION CODE REGISTER
I0
STACK POINTER
N
X = Undefined Value
ST72323 ST72323L
Z
C
0